7 research outputs found
Noncommutative Electrodynamics
In this paper we define a causal Lorentz covariant noncommutative (NC)
classical Electrodynamics. We obtain an explicit realization of the NC theory
by solving perturbatively the Seiberg-Witten map. The action is polynomial in
the field strenght , allowing to preserve both causality and Lorentz
covariance. The general structure of the Lagrangian is studied, to all orders
in the perturbative expansion in the NC parameter . We show that
monochromatic plane waves are solutions of the equations of motion to all
orders. An iterative method has been developed to solve the equations of motion
and has been applied to the study of the corrections to the superposition law
and to the Coulomb law.Comment: 13 pages, 2 figures, one reference adde
Null Deformed Domain Wall
We study null 1/4 BPS deformations of flat domain wall solutions (NDDW) in
N=2, d=5 gauged supergravity with hypermultiplets and vector multiplets
coupled. These are uncharged time-dependent configurations and contain as
special case, 1/2 supersymmetric flat domain walls (DW), as well as 1/2 BPS
null solutions of the ungauged supergravity. Combining our analysis with the
classification method initiated by Gauntlett et al., we prove that all the
possible deformations of the DW have origin in the hypermultiplet sector or/and
are null. Here, we classify all the null deformations: we show that they
naturally organize themselves into "gauging" (v-deformation) and "non gauging"
(u-deformation). They have different properties: only in presence of
v-deformation is the solution supported by a time-dependent scalar potential.
Furthermore we show that the number of possible deformations equals the number
of matter multiplets coupled. We discuss the general procedure for constructing
explicit solutions, stressing the crucial role taken by the integrability
conditions of the scalars as spacetime functions. Two analytical solutions are
presented. Finally, we comment on the holographic applications of the NDDW, in
relation to the recently proposed time-dependent AdS/CFT.Comment: 38 pages; minor changes, references added; text revised, minor
changes, final version published in JHE
Supersymmetric solutions of gauged five-dimensional supergravity with general matter couplings
We perform the characterization program for the supersymmetric configurations
and solutions of the , Supergravity Theory coupled to an
arbitrary number of vectors, tensors and hypermultiplets and with general
non-Abelian gaugins. By using the conditions yielded by the characterization
program, new exact supersymmetric solutions are found in the
model for the hyperscalars and with as the gauge group. The
solutions also content non-trivial vector and massive tensor fields, the latter
being charged under the U(1) sector of the gauge group and with selfdual
spatial components. These solutions are black holes with
near horizon geometry in the gauged version of the theory and for the ungauged
case we found naked singularities. We also analyze supersymmetric solutions
with only the scalars of the vector/tensor multiplets and the metric
as the non-trivial fields. We find that only in the null class the scalars
can be non-constant and for the case of constant we refine
the classification in terms of the contributions to the scalar potential.Comment: Minor changes in wording and some typos corrected. Version to appear
in Class. Quantum Grav. 38 page
The supersymmetric solutions and extensions of ungauged matter-coupled N=1,d=4 supergravity
We find the most general supersymmetric solutions of ungauged N=1,d=4
supergravity coupled to an arbitrary number of vector and chiral
supermultiplets, which turn out to be essentially pp-waves and strings. We also
introduce magnetic 1-forms and their supersymmetry transformations and 2-forms
associated to the isometries of the scalar manifold and their supersymmetry
transformations. Only the latter can couple to BPS objects (strings), in
agreement with our results.Comment: Some misprints and citations correcte
BPS equations in N=2, D=5 supergravity with hypermultiplets
With the general aim to classify BPS solutions in N=2, D=5 supergravities
interacting with an arbitrary number of vector, tensor and hypermultiplets,
here we begin considering the most general electrostatic, spherical-symmetric
BPS solutions in the presence of hypermultiplet couplings. We discuss the
properties of the BPS equations and the restrictions imposed by their
integrability conditions. We exhibit explicit solutions for the case of static
BPS black-holes coupled to one (the so called universal) hypermultiplet.Comment: 20 pages, v3 some corrections performed; we thank A.Van Proeyen for
the pointing ou